Industrial-rated circuit breakers are fitted with motor-operated devices for turning the circuit breakers ON and OFF either at the circuit breaker site or from a remote location. U.S. Pat. No. 4,042,896 describes a motor operator device that allows the circuit breaker to be conveniently converted from a motor operated-state to a manual-operated state by means of an external pushbutton and interface assembly. When the circuit breakers are engaged for motor operation, and a loss of motor control power occurs during a circuit breaker resetting function, the motor operator must be manually dissembled from the circuit breaker operating mechanism to allow the circuit breaker to be manually controlled.
When a large number of manufacturing processes are protected from a single motor-operated circuit breaker, some manufacturing down-time must occur to allow an operator to manually disengage the motor operator from the internal circuit breaker operating mechanism to manually reset the circuit breaker operating mechanism. The circuit breaker and associated electrical equipment are de-energized to protect the operator and equipment before the circuit breaker internal operating mechanism components are exposed and accessed. The motor operator is then re-connected with the circuit breaker operating mechanism. The circuit breaker automatically reverts to being controlled by the motor operator after the motor control power has been restored to the circuit breaker.
It would be economically advantageous to eliminate the requirement that the motor operator be manually dissembled from the circuit breaker operating mechanism each time such a loss of motor control power occurred. One purpose of the invention is to provide a motor operator unit with an interface assembly that would allow optional manual operation of the circuit breaker regardless of the state of the circuit breaker operating mechanism.